John Winters wrote: > Mary wrote; > > >The Irish pub where hang out in Ft. Lauderdale is a center for the sailing > >and yahting crowd. I ran into a fellow who designs racing hulls and he > >stated that they use teflon in the gelcote. Then they sand it with either > >200 or 400 grit to roughen it up. It was his opinion that an 18' kayak > >should gain 1/4 knot with a similar sanding. > > Ahhh Yes, the old naval architect in the pub bit. > > Having been one of those I can say with complete confidence that the worst > place in the world to get information on fluid dynamics is a pub where > naval architects hang out. > > Cheers, > John Winters > Redwing Designs > Specialists in Human Powered Watercraft > http://home.ican.net/~735769/ > Its not the architects, its the shaggy dogs they hang with. As a serious young dinghy racer (Geary 18, OK Dinghy, 505, Int. 14), I tried everything in the book. 1/4 knot is a HUGE increase, even at v=1.2(LWL)^.5, and the best goop we tried never showed an improvement beyong the systematic error of the model basin balance at David Taylor. My point was that graphite decreases the friction over sand and gravel, causing less scratching of the bottom. I don't think it makes the epoxy harder, just more scratch resistant due to the lower friction over the abrading surface. Roger *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Tue Nov 10 1998 - 06:26:19 PST
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